Structural and magnetic studies of 1% Ho:Gd_{0.99- x}La_x alloys

1% Ho:Gd_0.99-xLa_x (x=0.1, 0.25, 0.4 and 0.5) alloys have been studied using X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and Faraday magnetic susceptometry (FMS). XRD patterns show a single hexagonal type phase structure with lattice parameters depending on the Lanthanum concentration. VSM measurements were performed within the temperature range of 130-380 K and at maximum magnetic field of 13.5 kOe. FMS measurements were performed within the temperature range of 77-400 K and at magnetic field of 8 kOe. The sample with x=0.1 shows a ferromagnetic behavior up to a Curie temperature of 280 K whereas the three other samples are found to be paramagnetic within our temperature range of study. Furthermore, the saturation magnetization M_S for sample x=0.1 decreases with increasing temperature and the estimated magnetic moment by extrapolation of M_S versus T^3/2 to T=0K is (6.15±0.05) μ_B/f.u. The reciprocal of the molar magnetic susceptibilities of all samples appear to obey Curie-Weiss law in the paramagnetic region.